A battle may be brewing between cabinet and some backbench Liberals over Bill S-201, legislation which would make it an offence to discriminate against people based on their genetic test information.

The Commons justice committee meets Thursday morning for one of the Senate bill’s final hurdles — considering amendments at committee stage before it heads back to the House, a first test of support for the current version of the bill.

A government bill kit obtained by iPolitics indicates that the Liberals expect the Conservatives and NDP to support the bill — but it also warns Liberal MPs it could violate the Constitution by encroaching into provincial jurisdiction.

Liberal committee members, though, have expressedsupport for the bill as is, after a majority of constitutional experts testified the bill is fine as it stands.

But the justice minister’s office has expressed reservations.

“The government recommends deleting certain parts of the Bill to ensure that federal legislation does not intrude into areas of provincial jurisdiction and to address policy concerns,” the bill kit reads.

A more detailed letter Justice Minister Jody Wilson-Raybould sent the committee says the government supports the principle of the bill, but says it “is not in a position to fully support the approach” it takes. The letter suggests S-201 should be re-written so it doesn’t amend the labour code and doesn’t apply strong criminal law penalties over discrimination.

Sean Casey, parliamentary secretary to the minister of justice, said last week that it’s “reasonable” to expect amendments addressing the government’s concerns, but he conceded that the bill could pass as is — even if cabinet doesn’t like it.

Various members of all the main political parties have in the past tried to get versions of this kind of legislation through, but they’ve always stalled or failed. A promise for similar legislation was included in the Conservatives’ election platform last year.

The bill had cleared the Senate unanimously earlier this year after facing similar jurisdictional concerns there.

S-201 was launched in the Senate by Liberal Sen. Jim Cowan, and is being championed in the House of Commons by Liberal MP Rob Oliphant — both of whom were also thorns in the side of the justice minister through their vocal criticism of the constitutionality of the government’s assisted dying legislation earlier this year.